Determination of the enantiomeric composition of (+)‐terpinen‐4‐ol from sweet marjoram Origanum majorana L. using a chiral lanthanide shift reagent

Abstract 1H‐NMR examination of (+)‐terpinen‐4‐ol, performed in the presence of various molar ratios of a chiral lanthanide shift reagent Eu(hfc)3, showed that the enantiomeric composition of (+)‐terpinen‐4‐ol isolated from the essential oil of sweet marjoram is 73%(+): 27%(−). Peak assignment of the enantiomers was achieved by spiking the natural (+)‐enantiomer with the commercial (−)‐alcohol. The method will readily reveal adulteration of natural oils with racemic synthetics.